The purpose of /use is to allow you to use a consumable RP item (e.g potion but you can use whatever you want). The command broadcasts your usage of this item with a hoverable description of the item. This is so people can enforce the potion items to actually disappear when used.
I had a dream last night about a group of Musin who have the belief that if they somehow absorb souls of monsters and demons etc, then their lesser soul will grow.
the dream then just turned into Mouse Dark Souls.
still a cool dream though.